The present invention is directed generally to novel systems and methods for performing sputter deposition, and to optical devices manufactured using such systems and methods.
It is believed that in vapor deposition systems such as ion beam sputtering, magnetron sputtering, diode sputtering, thermal evaporation, electron beam evaporation, pulsed laser vaporization and cathodic arc vaporization, atoms or molecules ejected from a target are directed toward a substrate disposed on a wafer where they condense to form a film. In most cases, the deposited film shows variation in thickness across the wafer that the user would like to eliminate (for uniform deposition) or control (thickness gradient) to meet the needs of a particular application. It would be beneficial to provide a system that improves control of the deposition thickness on a wafer.
The present invention is directed to a system and method for controlling a circumferential deposition thickness distribution on a substrate. A motor rotates the substrate and a position sensor senses a rotary position of the substrate. At least one deposition thickness sensor senses the deposition thickness of the film on the substrate at multiple positions on a circumference of a circle centered about an axis of rotation of the substrate. At least one controller drives a vapor source used to emit material for deposition on the substrate. The controller is coupled to the positioning sensor and the deposition thickness sensor. The controller synchronously varies an emission rate of the material from the vapor source with respect to the rotary position of the substrate to control the circumferential deposition thickness distribution.
In accordance with a further aspect, the present invention is directed to a system and method for controlling a circumferential deposition thickness distribution on a substrate. A motor rotates the substrate and a positioning sensor senses a rotary position of the substrate. At least one deposition thickness sensor senses the deposition thickness of the film on the substrate at multiple positions on a circumference of a circle centered about an axis of rotation of the substrate. A target power supply drives a target used to sputter material on the substrate. A process controller is coupled to the positioning sensor, the deposition thickness sensor, and the target power supply. The process controller synchronously varies a sputtering rate of the target with respect to the rotary position of the substrate to control the circumferential deposition thickness distribution.
The invention also includes an optical filter created using the disclosed system and method.